Soldering iron



A. L. JOHNSON SOLDERING IRON Oct. 26, 1937.

Filed June 24, 1936 2 Sheets-Sheet l &

ATTOR INVENTOR- -Z1?fiarj IZZrzso/e,

' NEY Oct. 26, 1937. A. L. JOHNSON SOLDERING IRON Filed June 24, 1956 2 Sheets-Sheet 2 v l l f wl Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates, generally, to soldering irons and the invention has reference, more particularly, to a novel improved electric soldering iron.

Electric soldering irons as heretofore manufactured have generally been made from round steel tubing which is easily dented in use especially when holding the iron in a vice, since great pressure must be brought to bear to hold the iron from moving. When the outer housing of the iron is thus dented or damaged, the heating element is often crushed or rendered useless thereby ruining the iron. Also, these irons have a tendency to roll when placed upon a metal plate or bench resulting often in damage to goods on the bench or to the iron should the same fall to the floor, or in the burning of the operators fingers or possibly the ignition of combustible material on the bench or floor. Furthermore, these irons have a tendency to overheat when laid down resulting in injury thereto.

The principal object of the present invention is to provide a novel construction of electric soldering iron that is of non-circular and preferably hexagon cross-section, the same having a strong housing providing flat surfaces that may be easily held in a vice without much pressure and hence without injury to the housing of the iron, the hexagon shape of the iron enabling the same to be laid down without the possibility of rolling and consequent resulting injury or damage, the hexagon shape also providing considerably more heat radiating surface than possible in a round iron of the same diameter so that when the iron is laid down and left on the circuit there is no possibility of the same overheating, especially when laid on a metal plate since the relatively large contact surface between the flat surface of the iron and that of the metal plate provides for rapid conduction of heat away from the iron.

Another object of the present invention lies in the provision of a novel electric iron of the above character that is so constructed and arranged as to be adjustable as to length, which is hermetically sealed, and which is easily and safely handled in use.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings wherein the invention is embodied in concrete form.

In the drawings:

Fig. 1 is a perspective view illustrating the novel electric iron of this invention in use.

Fig. 2 is a longitudinal sectional view of one form of the iron of this invention.

Fig. 3 is a view similar to Fig. 2 of a somewhat modified form of iron.

Fig. 4 is a sectional view taken along line 4-4 6 of Fig. 2.

Fig. 5 is a sectional view taken along line 55 of Fig, 3.

Figs. 6 and '7 are sectional views similar to Fig. 4 but of modifications, and 10 Fig. 8 is a part sectional View taken along line 8-8 of Fig. 6.

Similar characters of reference are employed in said views, to indicate corresponding parts.

Referring now to Figs. 1, 2 and 4 of the draw- 16 logs, the novel electric iron is shown as having a handle I that is longitudinally and axially recessed at 2 for receiving the tubular stem or shank 5 of the iron. A ferrule 6, preferably of fibre or other suitable heat insulating material, 20 is slidably mounted on the stem 5 and is provided with a tapered thread I for engaging a corresponding thread provided within the handle I. The part of ferrule 6 in the region of threads 1 is provided with longitudinally extending slots 8 that divide this part of the ferrule into radially yieldable finger portions, whereby when the handle I is screwed upon ferrule 6 these finger portions are pressed radially inwardly to firmly grip the stem 5, thereby fixedly securing the ferrule 6 and handle I upon the stem 5. Should it be desired to change the length of the iron it is merely necessary to unscrew the handle I from the ferrule 6 and then move this ferrule along the stem 5 to the desired position thereon, whereupon the handle I is again screwed onto the ferrule 6 to cause the same to grip the shank 5, thereby locking the handle I in its new position. Such an adjustment is shown in dash lines in Fig. 3. Thus the effective length of the iron may be increased as when it is desired to do soldering in difficultly accessible places, or decreased as when it is desired to pack the iron into a small place such as a tool kit.

The shank or stem 5 of the iron terminates in, i. e. is secured to the housing 9 of the iron, the said housing having a non-circular and preferably hexagonal exterior surface, as especially shown in Figs. 1 and l. Preferably, the housing 9 is made from solid stock, the same being provided with a cylindrical bore II] for receiving the cylindrical core H therein. Since the housing 9 is made from solid stock such as cold worked steel the same is very rigid and strong and, there- IQIB, can withstand considerable external crush- 28 for conformably abutting the flared mouth 25.

ing pressure, especially adapting the iron for use in a vice as shown in Fig. 1. preferably made of bronze, since bronze has high heat conducting ability and is slow to oxidize, the same having a far longer length of life than steel or copper cores.

The core H has an electric heating element l2 thereon, the said element preferably consisting of a coil of suitable resistance wire insulated from the core I! by sheet mica, the whole being retained fixedly upon the core I l as by sheet metal clamps l3. Electric energy is supplied to the heating element cable It by means of leads l5 and I6 that extend through an insulating tube I! contained within the shank 5 and have their forward endswrapped around and secured to the terminal leads l8 and N3 of the heating element I2, the said terminal leads being shown extending through apertures The rear ends provided in an insulating disk E9. of leads l5 and I6 are secured to terminal posts or screws 28 carried by an insulating partition 2! that is fixed in the rear endportion of the shank 5 ofthe iron. The leads of cord or cable l4 are also secured to the screws 20, the cord Hi being provided with the usual receptacle plug 22.

In order to retain the core II in fixed position within the bore I!) of the housing 9, the said core is provided with a forward annular flange or radially enlarged portion 23 that fits in a conforming enlarged portion of the bore l0. Preferably the portion 23 of the core has a tight fit in the enlarged portion of bore 10, the said portion 23 abutting an annular shoulder 24 provided within the housing 9.

If desired, the enlarged portion 23 of the core may be brazed or welded to the housing 9, thereby rigidly holding the core in place within this housing. The outer or forward end portion of the-core II is provided with a flared mouth 25 leading to a circular axial threaded recess 26 adapted to receive the threaded shank of the tip This tip is provided with a beveled portion of the core ll, thereby obtaining excellent heat conduction from the core I l to the tip 21. If desired, insulation 29, such as asbestos may be inserted between the heating element l2 and the inner wall surface of the housing 9 and this insulation may be extended so as to surround the insulating tube ll within the stem 5, the said insulation serving to prevent excess heat conduction to the housing of the iron. This insulation 29 may be omitted, however, since the stem E'remains relatively cool in the absence of this (see Fig. 3) insulation; The enlarged portion 23 of the core serves to effectively seal the 'forward end of the housing 9 and if desired, the rear or free end of the shank 5 may also be sealed as by surrounding the leads I 5, l6, and insulating partition 2! with a suitable sealing means, such as wax compound, or the partition 2! may be made cylindrical to completely fill the hollow interior of the free end portion of shank 5, in which case the same is provided with holes for accommodating the leads [5, l6, (see Fig. 3).

In use, the novel iron of this invention heats up rapidly owing to the extremely good heat conduction between core II and tip 2'1. Owing to the novel structure of the housing 9. of the iron, the same is exceedingly strong and is easily clamped and fixedly held in a vise with but little pressure owing to the presence of the flat surfaces on the exterior of the iron. Also, these flat surfaces enable the iron to be laid down on The core H is l2 from the electric cord or fiat supporting surfaces, as shown in Fig. 1, without danger of rolling and consequent resulting damage or injury. The hexagonal surface of the housing 9 provides a larger heat radiating surface than a cylindrical iron, so that the housing of the iron of this invention remains relatively cool in use, especially when laid upon a flat metal surface. Inasmuch as core ll only contacts with the housing 9 at the front end of this housing through the enlarged portion 23, the stem 5 of the iron remains relatively cool so that the handle I remains cool at all times which is desirable in use.

In the form of the invention shown in Fig. 3,

parts which are similar to corresponding parts of Fig. 2 are correspondingly numbered. In this form of the invention a sliding or plug type tip 30 is used and the core structure is modified somewhat to accommodate the same. Thus the core Si in this form of the invention is made hollowto provide a cylindrical aperture 32 for slidingly receiving the tip 30, a cross pin 33 being carried by the rear portion of the core 3| tolimit the rearward movement of the tip 30; The core Si is provided intermediate its length with an annular flange or enlarged portion 34 that is adapted to abut against an annular shoulder 35 provided in the hollow cylindrical interior bore of the hexagonal housing 9'. The mouth portion of the housing 9 is internally threaded at 36 for receiving a nut 3'! that serves, by abutting the flange 34, to rigidly grip this flange between shoulder 35 and this nut 31, thereby locking the core 3! in place and preventing its turning.

A set screw 38 extends through an aperture in the housing 9 and is threaded through an aperture in the flange 34 for engagingthetip 3D to thereby lock this tip in desired longitudinally adjusted position. This screw 38 also acts as a check to prevent any possible turning of the core 3i within housing 9'. An insulating plug 39 projects-into the hollow interior of core 3| and takes the place of the insulating disk I9 of the form of the invention shown in Fig. 2. The novel electric soldering iron of Figs. 3 and 5 possesses the previously mentioned advantages of the iron of Fig. 2 with the additional feature that the tip 38 is adjustable as to length.

' If desired, the core of the iron may be made in non-circular shape to fit into a conforming aperture or recess provided irrthe housing, thereby positively preventing the core from turning within the housing. Such a structure is shown in Figs. 6 and 8 wherein the core II is similar to core ll shown in Figs. 2 and 4 except thatcore H is of hexagonal shape for fitting within the hexagonal recess or bore 49 provided in the housing 4!. In this structure the core flange 23 is also hexagonal. Otherwise the structure of Figs. 6 and 8 is similar to; that of Figs. 2 and 4.

If desired, the iron housing may be circular in exterior configuration as illustrated in Fig, '7, the same having a non-circular interior recess or bore similar to that of Fig. 6rfor preventing the turning of the core. In Fig. 7 the housing 62 is shown as having a hexagonal bore and a cylindrical exterior surface. In the eventv that the cores of the various forms of the iron should become corroded, or the heating elements carshank 5 and the leads l5 and f6 disconnected 15 from screws 20. This removal of the cores is especially easy of accomplishment in the form of the invention shown in Figs. 3 and 5, wherein by removing the set screw 38 and the nut 31, the core 3| and heating element may be readily removed and a new core and/or heating element substituted therefor, if desired. When removing the core and heating element, the leads l5 and I6 are drawn forwardly through the apertures provided therefor in the insulating tube ll, so that the leads are removed along with the heating element.

As many changes could be made in the above construction and many apparently widely dif ferent embodiments of this invention could be made without departing from the scope thereof, as defined by the following claim, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

In a soldering iron of the character described, a non-circular housing having a stem projecting from its rear end portion, a handle mounted on said stem, a core contained within said housing, a heating element surrounding said core within said housing and spaced inwardly from the walls thereof, said heating element having supply leads extending rearwardly through said stem for connection to a source of electrical supply, said core having a forward annular projection engaging a conforming annular recess provided in the wall of said housing, means for securing said projection within said recess to fixedly retain said core within said housing, and a tip carried by said core.

ARTHUR L. JOHNSON. 

